Page 77 - WCS - Electrical

belt is shown in the figure below.
2
x (4.86) cm
=
= 21.65 cm
2
4 Find the area, if the radius is 12.4 cm and the perimeter
of a sector of a circle is 64.8 cm.
Given:
Perimeter P
= 64.8 cm
Solution:
Radius r
= 12.4 cm
To find:
x 2πr unit
Length  =

Area A = ?
A
Solution: Area A = x πr unit 2 2 5 Find out the length of the belt , if the arrangement of a
210 0

Perimeter P =  + 2r unit = 360 0 x 2 x x 30 = 110 cm
 = P - 2r unit WORKSHOP CALCULATION & SCIENCE - CITS
= 64.8 - 2 (12.4) cm Length  = x 2πr unit
B
= 64.8 - 24.8 = 40 cm
0
DAF (Distance Across Flats) = x a unit
105
lr 40  12.4 = 0 x 2 x x 5 = 91.7 cm

360
Area A = unit = DAC (Distance Across Corners) = 2 x a unit
2
2 2
=  +  + 2 x 214 cm
1 Find out the perimeter, area, DAF and DAC of a regular hexagon whose side is 2cm.
= 248 cm 2 A B
(DAF - Distance Across Flats)
= 110 + 9.17 + 428 cm
(DAC - Distance Across Corners)
= 547.17 cm
Given: Side of hexagon (a) = 2cm
Hexagon To Find: P = ?, A = ?, DAF = ?, DAC = ?
Solution:
Perimeter of hexagon (P) = 6a unit
= 6a unit = 6 x 2 cm = 12 cm
3
2
Area of hexagon A = 6   a unit 2
4
Side = a unit
Perimeter P = 6a unit = 6  1.732  2 2
4
3 2
2
Area A = 6   a units (Area of 6 equilateral triangle) = 10.392 cm 2
4
DAF (Distance Across
DAF (Distance Across Flats) = 3  a unit
Flats) = 3  a unit
DAC (Distance Across Corners) = 2 x a unit
1 Find out the perimeter, area, DAF and DAC of a regular = 3  2 = 1.732 x 2
hexagon whose side is 2cm.
= 3.464 cm
(DAF - Distance Across Flats)
DAC (Distance Across
(DAC - Distance Across Corners) Corners) = 2 x a unit
Given: Side of hexagon (a) = 2cm = 2 x 2 = 4 cm
To Find: P = ?, A = ?, DAF = ?, DAC = ?
st
68 WCS - Electrician & Wireman : (NSQF - Revised 2022) - 1 Year : Exercise 1.7.26
Ellipse

Major axis AB = 2a
Half of Major axis OB = a,
Minor axis CD = 2b

Half of Minor axis OC = b
Area of ellipse A = x a x b unit²

64

CITS : WCS - Electrical - Exercise 5